I am new to this site and would like to learn about Skybox f5. I have seen these advertised on e-bay between £40 and £140. The more expensive ones and giving a free gift of between 1 & 2 years. Is it necessary to have this free gift and will it work for the time stated. As I am sure you can tell I am a complete novice and would like some guidance. PS. I do understand what the free gift is but not how it works in a technical way.